The LISST-25 is a submersible laser-scattering instrument
that shows true volume concentration and mean size. It is a
field instrument of in-situ measurements that overcomes the
historical problem of calibrations changing with particle
size. The LISST-25 has two specially designed detectors that
measure forward scattered light to deliver total particle
volume and total particle area concentrations. The ratio of
these concentrations, total volume to total area, determines
the Sauter Mean diameter (SMD).
Data downloaded and displayed on a computer screen shows
the volume concentration of particles, the SMD, and optical
transmission. The calibration of the instrument remains
constant so long as the size of particles is within a
specified 200:1 range.
In addition to the distant attraction of a single
calibration capability, the LISST-25 is a self-contained unit
designed for the rigors of field deployment. It is a
submersible compact instrument that includes optics,
electronics, a battery pack, and a programmable data logger.
Windows '95/'98/NT software is supplied to process raw data
into a time series of particle volume concentration, optical
transmission, and the Sauter Mean Diameter. The results can be
saved in ASCII format.
